it may lower your ability to fight infections. serious, sometimes fatal, events including infections, tuberculosis, lymphoma, other cancers, and nervous system and blood disorders have occurred. before starting enbrel, your doctor should test you for tuberculosis and discuss whether you've been to a region where certain fungal infections are common. don't start enbrel if you have an infection like the flu. tell your doctor if you're prone to infections, have cuts or sores, have had hepatitis b, have been treated for heart failure, or if, while on enbrel, you experience persistent fever, bruising, bleeding, or paleness. if you've had enough, ask your dermatologist about enbrel. he is a good little monkey and always very curious. one day george got an important letter. he's built a rocket ship to travel into space."